the format of the calibration data blob is proprietary. The SDK only provides procedures for getting the calibration from the tracker, for setting the calibration on the tracker, and for extracting the calibration point data items. Not for manipulating the calibration as such.
But I guess you could just record a few calibrations and see how they work for some test subjects without any manipulation?
And of course it depends on your application as well. If you don’t need high accuracy then it might work perfectly fine without user calibration.